The long term goal of this research is to elucidate the mechanism/s by which neurons direct the path of axonal growth, find appropriate postsynaptic cells and establish and maintain synaptic contact. The underlying assumption made is that all of these events are under the control of information encoded in the genome, although how prominent and direct a role genomic information plays remains to be established. All observations and experiments proposed are to be carried out using the fruitfly Drosophila melanogaster with the specific aims of: 1) defining the relationship of ectopic sensory tissue to normal sensory centers in the brain, 2) defining the function of mutations at a genetic locus (CB8) which seems to specifically involve either the determination, differentiation or maintenance of imaginal CNS, 3) pursuing the temporal and spatial interaction of the compound eye and optic lobe during development using mutations at the ro, un and Gl loci and 4) beginning the genetic and biochemical analysis of the enzyme responsible for the initial step in the synthesis of glycoproteins involving N-linked oligasaccharides.